Table 4-2. Organizational Troubleshooting-Continued.

TM 5-4120-386-14

Table 4-2. Organizational Troubleshooting - Continued.

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

3. EVAPORATOR OR CONDENSER FAN MOTOR FAILS TO OPERATE - Continued

Disconnect condenser fan motor relay. Actuate primary contacts with

Step 5.

24 volt DC source, then check continuity of contacts that should be

closed.

Replace bad relay. (Refer to paragraph 4-25.)

Inspect for bad evaporator fan speed control switch by checking

Step 6.

continuity with ohmmeter.

Replace bad switch. (Refer to paragraph 4-24.)

Inspect mode selector Rotary switch for improper adjustment of

Step 7.

damper.

Replace bad switch. (Refer to paragraph 4-24.)

4. COMPRESSOR WILL NOT START

Disconnect the power source before performing any troubleshooting function.

Make sure that compressor or control circuit breakers or selector

Step 1.

switch is properly set.

Make continuity check of control circuit to determine whether open

Step 2.

circuit exists.

Repair open circuit or replace wire.

(Refer to Wiring Diagram E-1.)

Step 3. Check continuity across primary winding and across secondary winding

of control transformer to see whether windings are good.

Replace bad transformer. (Refer to paragraph 4-29.)

Step 4. Apply 30 volts AC across side input terminals; check for 24-28 volts DC

across output terminals (marked + and -) of rectifier.

Replace bad rectifier. (Refer to paragraph 4-28.)

4-16